Why: Hagan, a state senator from Shelby, North Carolina, is the underdog for a seat that's gone Republican every year since 1972. While not the first choice of Washington Democrats, she kept pace with Dole in polls throughout the summer -- at one point holding a slim lead over the first-term incumbent. Dole certainly appears on the defensive -- lowering her profile as a Republican by joining around a dozen other incumbents in skipping the GOP convention in Minneapolis. Smelling blood, the Democratic Senatorial Campaign Committee hopes to invest up to $7 million in Hagan's campaign.

The race is also, notably, a rare Senate contest between two female major-party candidates. Hagan is known to be feisty, while Dole, a state celebrity in her own right, is more controlled and consistently conservative. The race should also be a referendum on the force of black-voter turnout in 2008. Obama's impressive victory in May's Democratic primary and investment in ads and get-out-the-vote drives in the state suggest Democrats are ready to play in the coastal South.

Why: This race in Mississippi, the eighth special election this year, confirms the extent to which Republicans are playing defense. Musgrove and Wicker are vying for the opportunity to serve out the rest of retired Sen. Trent Lott's term, which ends in 2012. The men traded the lead in polls throughout the summer, with Wicker opening up a nine-point lead by late July. It's remarkable that a Mississippi seat is even competitive for Democrats, who haven't had a representative in the Senate in 20 years. But these days, anything is possible: Wicker's move from the House to the Senate in December allowed Democrats to win a special-election upset this spring in a district that went for George W. Bush by 25 points in 2004.

The optics of a Senate pickup in Mississippi are irresistible for Democrats. As a former governor, Musgrove has high name recognition and a decent fundraising team but is battling his own high-profile electoral defeat at the hands of current Gov. Haley Barbour—who appointed Wicker to the vacant seat after Lott's retirement. For his part, Wicker will have to push back against the flagging Republican brand, and hard. Still, like the Dole-Hagan race, high black turnout in Mississippi (whose Democratic primary Obama won by a huge margin) could give Musgrove a needed boost.

Why: This race is like the 2008 presidential election in miniature. Madia, an attorney who served a six-month tour as a Marine Corps lawyer in Iraq, frequently emphasizes his story as "the son of immigrants." The 30-year-old beat State Sen. Terri Bonoff -- a two-term legislator with strong institutional backing -- in a protracted primary race. Madia's moderate credentials (he was a Republican until 2004) and legal background earned him endorsements from diverse interest groups.

Paulsen is a conservative, former state House majority leader who styles himself a maverick and who, in his first few campaigns, pushed back against political action committee money, promised fiscal restraint, and took a conciliatory approach on the environment. Nevertheless, he ran with strong party support for the suburban seat held by Republicans for nearly a half-century. But this year, many analyses list Minnesota's 3rd as one of the few genuine "toss up" races. It will also be among the most expensive: Paulsen has $1.2 million in cash on hand, compared to Madia's near $1 million -- a surprising amount of which has come from newly political Indian American donors across the country. (The Democratic Congressional Campaign Committee has also pledged over $1 million.) Madia is a marquee example of the "Next Generation" veterans who have come out in support of the Democratic platform this year.

New Jersey, 5th District

Who: Rep. Scott Garrett (R) vs. Rabbi Dennis Shulman (D)

Why: Shulman would be the first rabbi elected to Congress. He's received strong backing from the "pro-Israel, pro-peace" group J Street and other progressive organizations, even as he campaigns in a traditionally red district against a three-term incumbent. The district, which runs from affluent old-money suburbs to working-class satellites of New York City, has an unambiguous commuter culture in which energy prices are a major campaign issue. The 58-year-old Shulman has been one of only a few local Democrats to successfully make hay of the issue, producing humorous spots tying Garrett to big oil.

Garrett, who is slightly favored to win re-election, could be classified as a classic New England "Rockefeller Republican" -- the class of socially liberal, fiscally conservative legislators who pepper the Atlantic seaboard. Garrett, backed by the Club for Growth, was the only one in the New Jersey delegation to vote against the energy bill in December, has been a strong supporter of the war in Iraq, and voted against the Americans with Disabilities Act renewal -- a fact that is extra poignant because Shulman is blind. Shulman trails in fundraising, but the DCCC's classification of the matchup as an "emerging race" means more support for the Democrat could materialize. Shulman, a clinical psychologist by training, gives a whimsical stump pitch against Washington: "It may very well take a blind man to show Congress the light."

GOVERNOR:

Indiana

Who: Gov. Mitch Daniels (R) vs. former Rep. Jill Long Thompson (D)

Why: Daniels is the former director of Bush's powerful Office of Management and the Budget who made his personal fortune with drug giant Eli Lilly. Nicknamed "Dick Cheney's Dick Cheney," he was one of the architects of Bush's $1.3 trillion tax cut and assumed the Indiana governorship in 2004. Thompson is attempting a bit of a comeback—she served in Congress until she was ousted in the 1994 Republican landslide, after which she worked in the Clinton Department of Agriculture. Early polling showed her neck-and-neck with Daniels going into the general. However, Thompson's Washington experience has allowed Daniels to paint her as out of touch with Hoosiers, and she's since fallen behind him in the polls.

Still, Daniels is particularly vulnerable because of his close ties to Bush. And this year's up-ticket race could make all the difference for Thompson. Indianapolis and its suburbs, plus the northwest corner of the state close to Obama's Chicago, are fertile territory for Democrats this year. And Thompson's experience farming and managing federal rural development should play well in the southern part of the state, which could otherwise be Daniels country. Backed by Emily's List and unions like the United Auto Workers, she has kept pace with Daniels in fundraising in 2008, though he has almost triple her cash on hand. If she pulls out the win, Thompson would be the first woman to be elected governor of Indiana, and she is already the first woman to be nominated for the position by a major party.